Buffers Flashcards
What happens when strong acids are placed in water?
Strong acids give a large number of H3O+ ions when placed in water
What happens when weak acids are placed in water?
They only partially dissociate when placed in water
What happens to H+ in water?
H+ always combines with an H2O molecule to form H3O+
What does the ionisation constant show?
It shows the direction of the reaction
What is Ka?
The acid ionisation constant
What is Kb?
The base ionisation constant
What does a large value of Ka mean?
It means there are many H+ ions in solution -> a strong acid
What does a large Kb value indicate?
It indicates many OH_ ions -> a strong base
What is a weak acid?
One that only partially dissociates in water
Give an example of a weak acid.
Ethanoic acid
What is the conjugate base of a weak acid?
A strong base
What is the conjugate acid of a weak base?
A strong acid
What is a buffered solution?
A buffered solution resists change in pH when small amount of acids or bases are added or when dilution occurs
What are buffered solutions made of?
3
A mixture of weak acid and its salt or a weak base and its salt
An acid and its conjugate base
A base and its conjugate acid
How do buffers work?
They work by removing small quantities of H+ and OH- ions that are added to it
